Provide a better error and a suggestion for `Fn` traits with lifetime params
Given `Fn`-family traits with lifetime params in trait bounds like `fn f(_: impl Fn<'a>(&'a str) -> bool)`, we currently produce many unhelpful errors.
This PR allows these situations to suggest simply using Higher-Rank Trait Bounds like `for<'a> Fn(&'a str) -> bool`.
Fixes https://github.com/rust-lang/rust/issues/103490.